This article assumes you already have at least on location defined and that you have unrestricted access to admin backend.
Additional notes:
The opening hours sections allows you to add several opening and closing hours per day. If you are opening and closing multiple times a day.
If your location is temporarily closed it might be easier to change the opening rule of the location on the bottom of the edit page from "Location is open based on opening hours" to "Location is always closed" and the change it back after you reopen.